Gary Johns has been a staunch critic of charities that conduct public advocacy work

Labor MP asks Mr Turnbull to reverse the appointment

More recently he has been a staunch critic of charities that conduct public advocacy work.

Labor MP Andrew Leigh has called for the Prime Minister to reverse the appointment, arguing Dr Johns is not fit to hold the lucrative position given his controversial history and "trenchant" criticism of the charity sector.

"If Malcolm Turnbull has any gumption, any leadership, he must step in today, overrule Michael Sukkar and announce that Gary Johns will not head the charities commission," Mr Leigh told reporters at Parliament House.